城市污水厂污泥快速好氧堆肥技术研究

以污泥静态堆肥工艺为基础,针对上海曲阳污水处理厂的脱水污泥进行动态好氧堆肥处理工艺研究,重点研究了控制参数和评价参数(温度、含水率、pH、水溶性有机碳和发芽指数等)变化规律.结果表明:污泥堆肥过程中,含水率、物料温度、水溶性有机碳、发芽指数等指标变化规律性强,效果指示性明显,均可选作堆肥腐熟度的表征参数或评价参数.在优化工艺条件下,通过添加适量的木屑和回流物料,控制物料初始含水率在60%±2%时,堆肥处理可以实现顺利升温并在>55℃维持4d,100%杀灭了病原菌;14d反应周期结束时,物料含水率显著降低,水溶性有机质降解50%左右,出料松散且无臭味,堆肥产品腐熟,卫生学指标达到了我国标准和美国EPA污泥产品A类标准.     

Experimental study on an ultra high-rise building evacuation in China

With the development of modern cities, more and more ultra high-rise buildings have been built. Emergency evacuation of such buildings becomes one of the major concerns for building designers, building occupants and governments, especially after the disaster of 9/11. In this study we designed three experiments to investigate the process of ultra high-rise building evacuation. The experiments were performed in Shanghai World Financial Center, which is about 470 m tall. In the first experiment, the evacuation of a single pedestrian from the top floor to the first floor was performed. Movement characteristics such as mean speed and the time needed for evacuation were analyzed. In the second experiment, the mass evacuation process was captured by video cameras and the data were extracted out manually. The evacuees were distributed initially on floors 12–17, and were asked to evacuate through a staircase onto the refuge floor. On the refuge floor, i.e. the 6th floor, the evacuees were required to transit into another staircase to keep moving down to the ground floor. The characteristic space–time curves for each evacuee were extracted and analyzed. Parameters such as the mean speed and the evacuation time, as well as the characteristic of the transit process from one staircase to another were investigated. We at last mimicked and discussed the process of lift evacuation for an ultra high-rise building in the 3rd experiment. Evacuees located on the 41st and 65th floor were asked to move downward by stairs until they came to the refuge floors, where they would evacuate to the ground floor by lifts. The time characteristic of the mixed evacuation strategy was discussed. The basic data obtained from the experiments are useful for building designers and can be used to validate and refine ultra high-rise building evacuation models.     

Dye removal by activated carbon produced from Agave americana fibers: stochastic isotherm and fractal kinetic studies

Environmental Science and Pollution Research - The present work investigates the use of Agave americana fibers (AGF) as a precursor for activated carbon (AC) preparation via chemical activation...     

Air pollution associated with cognitive decline by the mediating effects of sleep cycle disruption and changes in brain structure in adults

Environmental Science and Pollution Research - The effects of air pollution on sleep and dementia remain unclear. The objective of this study was to investigate the effects of air pollution on...     

Prenatal diagnosis of respiratory chain deficiency by direct mutation screening

Respiratory chain deficiency (RCD) is responsible for a clinically heterogeneous group of early-onset untreatable disorders. Enzymological prenatal diagnosis (PD) can only be offered to a fraction of families. Moreover, due to the two-fold genetic origin of the respiratory chain (nuclear and mitochondrial DNA) and owing to the large number of nuclear genes involved in the respiratory chain assembly, maintenance and functioning, the identification of the disease causing gene in a given family remains challenging. Here, we report on PD of RCD by direct screening of NDUFV1, SDH-Fp, SCO1 and SURF1 mutations in five unrelated families with complex I, II and IV deficiency, respectively. The identification of the disease-causing gene in a given family with RCD is a major issue to provide both adequate genetic counselling and early, reliable PD. Copyright © 2001 John Wiley & Sons, Ltd.     

The oldest African fox (Vulpes riffautae n. sp., Canidae, Carnivora) recovered in late Miocene deposits of the Djurab desert, Chad

We report on the oldest fox (Canidae) ever found in Africa. It is dated to 7 Ma based on the degree of evolution of the whole fauna. It belongs to a new species. Its overall size and some morphological characteristics distinguish the Chadian specimen from all the other foxes. The presence of Vulpes and of the genus Eucyon in slightly younger African locality, as well as in southwestern Europe in the late Miocene, may indicate that canids migrated in Europe from Africa through a trans-Mediterranean route.